Windows Phone posted the largest year-over-year increase among the top five smartphone platforms, and in the process reinforced its position as the number 3 smartphone operating system. Driving this result was Nokia, which released two new smartphones and grew its presence at multiple mobile operators. But beyond Nokia, Windows Phone remained a secondary option for other vendors, many of which have concentrated on Android. By comparison, Nokia accounted for 81.6% of all Windows Phone smartphone shipments during 2Q13.

Over the past 12 months, Windows Phone went from 3.1% market share to 3.7%. This means that while shipments of Windows Phone devices are growing, they're barely growing any faster than the industry as a whole. Still, it's crazy to see there's less than a 10 percentages points difference between Windows Phone and iOS.

Another potential problem is that Microsoft is effectively entirely dependent on Nokia. If Nokia falters, Windows Phone falters. Other vendors have essentially lost all interest in the platform, and as such, Microsoft has a a very strong impetus in keeping Nokia going. Still, I'm pretty sure that the Surface phone is ready to go at a moment's notice.